Researchers made a surprising discovery when examining farmland treated only with organic fertilizers.
Sustainable agriculture is becoming more and more widespread. In France, 2.76 million hectares were cultivated organically at the end of 2023, or 10.4% of the agricultural area exploited in France, according to the Bio Agency. Last year, 5.6% of household food consumption was made up of organic products. It is in this context that a new study, carried out by researchers at Kansas State University, analyzed soils suitable for organic farming, and more specifically those treated with organic fertilizers.
They thus analyzed the soil of a corn field in Kansas treated with organic fertilizers, such as manure or compost, and without plowing for around twenty years. Experts made a surprising discovery, which they shared in the journal Soil Science Society of America : in organic fields, they found carbon, and in greater quantities than in fields that received chemical fertilizers or even cultivated without fertilizer.
By treating fields with natural manure, organic farming has promoted the life of micro-organisms underground and in particular microbial carbon. The carbon will also attach to minerals in the soil, thus creating long-term storage. Being able to retain carbon in this way is very beneficial because it can limit the gas that ends up in the atmosphere, the quantity of which has only increased in recent years and therefore contributes to global warming.
“To my knowledge, this is the first direct evidence of the mechanisms by which organic amendments improve soil health, microbial diversity and carbon sequestration,” said Ganga Hettiarachchile, professor of soil and water chemistry. environment at Kansas State University. Soils on Earth currently store 10 times the amount of carbon present in the atmosphere, so it is important not to let it escape by degrading these lands. The use of organic fertilizers can therefore make it possible to improve this storage, according to the conclusions of this research.
“Studies like this will help us move towards more sustainable and regenerative agricultural practices that will protect our soil and environment while helping to feed a growing population,” added the specialist.